Journal
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
Volume 676, Issue -, Pages 28-37Publisher
ELSEVIER SCIENCE SA
DOI: 10.1016/j.msea.2016.08.090
Keywords
Plasma arc welding (PAW); High-strength low-alloy (HSLA) steel; Tempering temperature; Conventional tensile strength; Notched tensile strength
Categories
Funding
- Chung-Shan Institute of Science and Technology, Taiwan [XB92035P]
Ask authors/readers for more resources
This study prepared high-strength low-alloy (HSLA) D6AC weldments using a plasma arc welding (PAW) process. The PAW weldments were then tempered at temperatures of 300 degrees C, 450 degrees C, and 600 degrees C for 1000 min. Microstructural characteristics of the weld in as-welded HSLA-D6AC, tempered D6AC, and tensile-tested D6AC were observed via optical microscopy (OM). We also investigated the hardness, tensile strength, and V-notched tensile strength (NTS) of the tempered specimens using a Vickers hardness tester and a universal testing machine. The fracture surfaces of the specimens were observed using a scanning electron microscope (SEM). Our results show that the mechanical properties and microstructural features of the HSLA weldments are strongly dependent on tempering temperature. An increase in tempering temperature led to a decrease in the hardness and tensile strength of the weldments but led to an increase in ductility. These effects can be attributed to the transformation of the microstructure and its effect on fracture characteristics. The specimens tempered at 300 degrees C and 450 degrees C failed in a ductile-brittle manner due to the presence of inter-lath austenite in the microstructure. After tempering at a higher temperature of 600 degrees C, martensite embrittlement did not occur, such that specimens failure was predominantly in a ductile manner. In the NTS specimens, an increase in tempering temperature led to a reduction in tensile strength due to notch embrittlement and the effects of grain boundary thickening and sliding. Our findings provide a valuable reference for the application of HSLA-D6AC steel in engineering and other fields. (C) 2016 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available